Method of imparting to hydrophobic textile materials antistatic properties



United States Patent 3,471,319 METHOD OF IMPARTING T0 HYDROPHOBICTEXTILE MATERIALS ANTISTATIC PROPERTIES Reginald L. Wakeman,Philadelphia, Pa., assignor to Millmaster Onyx Corporation, New York,N.Y., a corporation of New York No Drawing. Filed July 22, 1968, Ser.No. 746,293 Int. Cl. C08j 1/44; C09k 3/16 US. Cl. 117139.5 4 ClaimsABSTRACT OF THE DISCLOSURE A process for treating hydrophobic textilematerials to give them antistatic properties which comprises applying anantistatic agent to the textile materials while maintaining the pH ofthe agent on the acid side, and then curing the antistatic agent insitu, the antistatic agent being a water-soluble, linear polytertiaryamine having at least one terminal tertiary amino group and the linearchain being interrupted by a plurality of tertiary amino groups.

This invention relates to an improved process for treating hydrophobictextile fibers, filaments, yarns, woven and non-woven fabrics, knittedgoods and the like, to give such materials antistatic properties whilesignificantly improving the whiteness thereof after being laundered.

It has heretofore been proposed to treat textile materials of the abovetype with the same type of water-soluble, linear polytertiary amines asthose utilized herein and more fully described hereinafter. However,such prior treatment was made while maintaining the pH of the antistaticagent on the alkaline side. Such prior treatment has proved to beextremely effective and provides a very durable antistatic finish, butthe whiteness of the treated material after laundering has not been asgreat as is sometimes desirable.

It has now been discovered that if the treatment is conducted while thepH of the treating agent is on the acid side, there is a significantimprovement in such whiteness characteristic with only a small sacrificeof antistatic durability. Preferably, a catalyst such as zinc fluoborateis also used in a proportion of about 0.05 to 1.0% by weight of theantistatic composition.

Polymeric amino condensation products for application to hydrophobictextile materials are well known to the art and can be produced byreaction of an alkylating diester of a water-soluble polyalkyleneglycol, specifically a polyethylene glycol dichloride, with a primaryaliphatic amine containing from one to twenty-two carbon atoms,preferably one of low molecular weight such as methyl amine, ethyl amineor hydroxyethyl amine. Such antistatic finishes and methods of makingthe same are described in US. Patent 3,070,552 issued Dec. 25, 1962.Products of this nature which are used as starting materials in makingthe antistatic compounds used in the present invention have thefollowing generic formula:

where R is an alkyl, alkenyl or hydroxyalkyl radical containing from oneto twenty-two carbon atoms; Z is CHZCH CHzCHgin which R is an organicdivalent radical and m and n are average numbers between 3 and 40; p isan integer having a value of at least 1; and Q and Q are either'secondary amino groups, N(R)H, or covalently linked chlorineoriginating with the intermediate polyethylene glycol dichloride (orequivalent ester-forming residues of an inorganic acid or of anorganically substituted sulfuric, phosphoric or sulfonic acid such asBr, I, SO CH OSO H and the like).

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Depending upon reaction conditions during the production of thesepolymeric amino condensation products, Q and Q may be either the same ordifferent end groups. Hence, the condensates may comprise any one, acombination of any two, or all three of the following species:

wherein R, Z and p are as just defined and X is chlorine or anequivalent ester-forming residue of the intermediate alkylatingpolyalkylene glycol diester as set forth above. As hereinabove setforth, these structural components of the polymeric amino condensatesare the starting materials of this invention and are hereinafterreferred to as polyamine species (1), (2) or (3). It is to be noted thateach of these starting materials has internal tertiary amino groups inthe chain which carries end groups that may be either secondary aminogroups or chlorine or its equivalent. Hence, they are polymeric tertiaryamines, but species (1) and (2) have at least one terminal secondaryamino group also. In the antistatic compounds used herein, at least oneof the end groups in each of the species is converted to a tertiaryamine radical. The preferred final products, however, have all theterminal amino radicals converted to tertiary amino groups.

The polyamines which are the starting materials for this inventionsulfer certain deficiencies by virtue of the nature of their end groupswhich, as just stated, may be either secondary amino groups orcovalently linked chlorine (or its equivalent) or both. Secondary aminogroups may cause yellowing of the material to which the finish isapplied. Terminal chlorine radicals provide a means for quaternizationof internal tertiary amino groups distributed along the chain of thecondensates, with attendant cross-linking which may cause gelation onstanding. The elimination of either one or both of these disadvantagesrepresents a major practical need of the textile industry.

It has now been found that such greatly improved characteristics can beimparted to the previously described amino condensates by converting aportion or all of the end groups present therein to tertiary amineradicals. Either the terminal secondary amine groups of polyaminespecies (1) and (2) or the end covalently linked chlorine (orequivalent) radicals of intermediate species (2) and (3) may beconverted to tertiary amine groups, or both may be so converted.

The products utilized herein correspond to the general formulaYZ[N(R)-Z] Y, where R is an alkyl, alkenyl or hydroxyalkyl radicalcontaining from one to twenty-two carbons, preferably methyl, ethyl orhydroxyethyl; Z is a divalent radical derived from the intermediatealkylating polyalkylene glycol diester, viz. polyethylene glycoldichloride, i.e.

wherein R is an organic divalent radical such, for example, as a glycolradical, a dibasic acid radical OCACO, wherein A is the intermediatedivalent radical of the dibasic acid or a diurethane radical OCNHANHCO,wherein A is again an intermediate divalent radical of the diurethane,and mi and n are average numbers between 3 and 40; p is an integerhaving a value of at least 1; Y is a tertiary amino radical, NR Rwherein R and K, may be the same or different alkyl, hydroxyalkyl,aralkyl or alkaralkyl radicals containing from one to ten carbon atoms;and Y is selected from the group consisting of 1) a tertiary aminogroup, -NR R wherein R and R have the same definition as R and R; butmay be either the same or different radicals, or (2) a secondary aminogroup, HNR, or (3) a halogen or the esterforming residue of an inorganicacid or of an organically substituted sulfuric, phosphoric or sulfonicacid such as Cl or other equivalent covalently linked radicaloriginating with the initial intermediate polyalkylene glycol alkylatingdiester used in producing the intermediate polymeric amines, forexample, Br, I-, SO H, SO CH SO H, -SO CH CH -C H SO and the like.

In producing the polymeric amines utilized herein which contain terminaltertiary amino groups, there are used, as starting materials, any of theabove described three species of polymeric amines.

According to one embodiment, terminal secondary amino groups present inspecies (1) and (2) are converted to tertiary amino end groups by anysuitable reaction such, for example, as by alkylation with an alkylhalide, specifically methylation with methyl chloride, or by reactionwith formaldehyde and formic acid in accordance With the conventionalSommelet and Ferrand method well known to those skilled in the art anddescribed, for example, in the Journal of the American Chemical Society55, 4571-4587 (1933). The terminal secondary amino groups of species (1)and (2) may also be converted into tertiary amino radicals bybenzylation with benzyl chloride or a substitution product thereof suchas methyl-benzyl chloride, ethyl-benzyl chloride, cuminyl chloride orchloromethyl mesitylene, for example. Normally, but not necessarily, itwill be advantageous to carry out alkylation or benzylation with ahalide in the presence of an acid acceptor such as sodium hydroxide orsodium carbonate. Any other suitable alkylating agent may be employed.Thus, for example, we may use dimethyl sulfate, diethyl sulfate,triethyl phosphite, triethyl phosphate, the corresponding butylderivatives and the like. Examples I to III illustrate the conversion ofterminal secondary amine groups to tertiary amine radicals.

A major advantage of these products is the marked reduction indiscoloration of textile materials treated therewith in contrast to thecolor developed by treatment with products containing secondary amineterminal groups. This is of great commercial significance especiallywhere whiteness or fidelity of pastel shades is imperative, mostparticularly in the treatment of textile yarns, filaments and fibers.

As previously pointed out, polyamine species (2) and (3) containterminal chlorine radicals which are organically bound, or other similarend groups originating with the alkylating polyethylene glycol diesterused in their preparation. These chlorine end groups or theirequivalents may be converted into tertiary amine radicals by reactionwith a secondary aliphatic amine containing from two to six carbon atomssuch, for example, as dimethyl amine, diethyl amine, diethanol amine,diisopropyl amine, diisopropanol amine and the like. This reaction maybe carried out in the presence or absence of acid acceptors such assodium hydroxide or carbonate, with or without pressure depending uponthe boiling point of the secondary amine employed, and with or withoutan excess of the theoretical amount of amine. The conversion of halideend groups to tertiary amine radicals is advantageous when it isanticipated that the ultimate conditions of use of the finished goodswill be such as to facilitate hydrolysis with consequent deterioration.As previously noted, terminal covalent chlorine or analogous groups ofpolyamine species (2) or (3) are potentially capable of giving rise togelation of these products on standing during storage by virtue ofcross-linking through quaternization of tertiary amino groups presentwithin the molecular chain. Conversion of these quaternizing end groupsto tertiary amino radicals eliminates this problem and increases thestorage stability of the antistatic finishes. Example IV will illustratethis conversion of terminal covalently linked chlorine atoms, or theirequivalent, to tertiary amino groups.

The water-soluble polymeric amines containing terminal tertiary aminogroups which are the object of this invention can be cured to yieldexceptionally durable antistatic finishes on hydrophobic fibers,filaments, yarns, fabrics and the like by curing the treated goods atelevated temperatures with a polyepoxide cross-linking agent. Themechanism of the reaction between polytertiary amines of the kind hereindescribed and polyepoxides is not understood at the present time,although various hypotheses can be advanced to explain it. Regardless oftheory, the fact is that modified polymeric amines of this inventionwhich contain terminal tertiary amine end groups may be cross-linked toform a durable antistatic finish by applying them to a hydrophobic fiberor fabric or other textile material, together with a suitablepolyepoxide and curing after drying. The cross-linking reaction isnormally carried out at temperatures between C. and C. in less than fiveminutes. In particular, it has been found useful to cross-link thesepolymeric amines with a product available under the trademark Eponite100, from the Shell Chemical Corporation, which is believed to be thereaction product of glycerine and epichlorohydrin. Curing can also becarried out with any water-solubilized or dispersed polyepoxidedescribed in British Patent 780,288 dated July 31, 1957.

If preferred, cross-linking may also be effected by curing withethylene-imino compounds containing a plurality of aziridinyl groupssuch, for example, as tris-aziridinyl phosphine oxide and the like, bythe methods described in copending application Ser. No. 268,590 filedMar. 28, 1963.

The polyaziridinyl compounds useful as the second component of suchtreating baths are organic compounds containing at least two aziridinylgroups and at least one hydrophilic group sufiicient to confer Watersolubility or ease of emulsifiability in water on the molecule, suchhydrophilic group or groups being non-reactive with the aziridinylgroup. Among the hydrophilic groups suitable for this purpose are thecarbamido and oxo as well as sulfide, sulfone and polyether groups.Examples of polyaziridinyl compounds useful in the carrying out of thisinvention are tris-l-aziridinyl phosphine oxide; tris-laziridinylphosphine sulfide; tris-l-(Z-methyl) aziridinyl phosphine oxide;tris-l-(Z-methyl) aziridinyl phosphine sulfide;1,6-bis-(N-ethylenecarbamido) hexane; 1,3-bis- (N-ethylenethiocarbamido)propane; 2,4-bis-(N-ethylenecarbamido) toluene;4,4-bis-(N-ethylenecarbamido) diphenyl ether; N-[tris-(l-aziridinyl)phosphoranylidene] acetamide; bis-(2-aziridinylethoxyethyl) ether;bis-(2- aziridinylethyl) sulfide; bis-(2-aziridinylethyl) sulfone;tris-(aziridinylmethyl) amine; dipotassium 2,4-diaziridinyl pentanoate;and the compound of formula:

where Z is the divalent radical of polyethylene glycol 400 derived byelimination of hydroxyl groups.

Other cross-linking agents which may be used to cure the products ofthis invention include polyethylene glycol dihalides and the like, inparticular polyethylene glycol 600 diiodide, as well as the dichlorideand dibromide which are somewhat slower in reaction than the diiodide.These agents may be selected from the group consisting of alkyleneglycols, aralkylene glycols and polyethylene glycols in which the twoterminal OH groups of the glycols are replaced by a member of the groupconsisting of chloride, bromide, iodide, sulfate, phosphate, methanesulfonate and toluene sulfonate groups.

The following examples wherein all percentages or parts are by weight,unless otherwise indicated, illustrate specific embodiments of ourinvention.

EXAMPLE I One mol of the dichloride of polyethylene glycol 600 wasreacted with 1.07 mols of methyl amine in ethylene glycol, the amount ofglycol being equal in weight to that of the dichloride. Sodium carbonatewas used as the acid acceptor and the reaction was carried out in themanner of Example 1 of US. Patent 3,070,552, the reaction being carriedto 94.6% completion as measured by ionic chloride in the reactionproduct which was diluted to a 20% active material.

To 500 grams of this 20% solution was added 6.7 grams of 36 B. sodiumhydroxide solution and 6.6 grams of benzyl chloride. The mixture washeated to 60- 70 C. and held at that temperature for 4 hours withagitation. At the end of this time, all of the secondary amine groupsoriginally present in the polymeric amine had been converted to tertiaryamino groups. Instead of benzyl chloride, equivalent amounts of methylbenzyl chloride, ethyl benzyl chloride, cuminyl chloride or chloromethylmesitylene may be used.

Thirty-six grams of water was removed from this solution by applicationof vacuum at 70 C. and the product was then applied to fabric andevaluated as follows.

An aqueous solution was prepared containing 29.6% of the above product,1.48% of Eponite 100 and 0.39% of Neutronyx 600, a nonionic wettingagent supplied by Onyx Chemical Corporation and consisting of anonylphenol polyglycol ether containing 9.5'mols of ethylene oxide. Thesolution was adjusted to a pH value of 3.5 with dilute hydrochloricacid, and 0.1% of zinc fiuoborate was added in aqueous solution; it wasthen used to impregnate a piece of Dacron taffeta fabric (Dacron is thetrade name of E. -I. du Pont de Nemours & Companys polyester fiber) in athree-roll padder with the roll pressure adjusted so as to give a 27%increase in the weight of the fabric after impregnation. The fabric wasframed, dried 2 minutes at 220 F. and then heated for 5 minutes at 250F.

The fabric thus treated had an electrical resistivity of 7.4)( ohms whenmeasured by AATCC Method 76- 1959 after conditioning at 30% RelativeHumidity and 75 F. and had an electrical resistivity of 1.2 10 ohmsafter having been laundered 20 times in an automatic washing machine at140 F. and with Tide detergent. An untreated sample of the same Dacrontaffeta fabric had an electrical resistivity of greater than 1X10 ohmswhen measured under the same conditions. A fabric with an electricalresistivity less than 1 l0 ohms as measured under the above statedconditions is accepted as having satisfactory antistatic properties bytextile chemists and processors.

EXAMPLE II To another 500 grams of the intermediate product of Example Iprepared by reaction of polyethylene glycol 600 dichloride with methylamine was added methyl chloride by slowly bubbling it into the 20%active reaction product held at 6070 C. The reaction was continued witha fine stream of methyl chloride passing through the solution until theionic chloride content increased from 0.323 milliequivalent per graminitially to 0.518 milliequivalent per gram and a test for secondaryamine groups showed their absence. Vacuum was applied to remove excessdissolved methyl chloride and the product evaluated for antistaticproperties in the following manner.

A piece of Dacron plain weave fabric was treated with an aqueoussolution containing 29.6% of the above product, 1.48% Eponite 100 and0.39% Neutronyx 600 just as described in Example I, but adjusted to a pHof 6.0 with hydrochloric acid, and with the addition of 0.1% of zincfluoborate, the impregnated fabric being heated for 2 minutes at 220 F.and then 5 minutes at 6 300 F. When tested by the procedure described inExample I, this sample had an electrical resistivity of 5.7 l0 ohmsinitially and 5.0 10 ohms after 10 launderings. Dacron twill weavetreated in the same manner gave similar results.

EXAMPLE III To 1000 grams of a 20% active solution of a polytertiaryamine prepared by the method of Example I was added 6 grams ofparaformaldehyde and the mixture was warmed with stirring to C. and heldthere until all of the paraformaldehyde dissolved. At this point thesolution was cooled to 30 C. and 23 grams of formic acid was addedslowly with agitation. Foaming occurred, but upon its cessation, afteraddition of all of the formic acid, the temperature was raised to 80 C.again and held there, with stirring for 2 hours. At the end of thistime, the reaction mixture was cooled to room temperature and 45 gramsof 36 B. sodium hydroxide solution was added to adjust the pH to 8.3.The product was evaluated for antistatic performance as follows.

The above product was applied to a piece of nylon tricot at a pH of 4.8and with the addition of the fluoborate catalyst, by a procedure exactlythe same as that described in Example I. The treated sample had anelectrical resistivity of 3.3)(10 ohms initially and 4.2 10 ohms after20 launderings.

Under the conditions of the above examples, in each case the antistaticcharacteristics were not quite as durable as those obtained by applyingthe same type of formulations on the alkaline side, but there was asignificant improvement in the whiteness of the treated and launderedfabrics.

In general, by methods similar to those of Example I to III above, anyof the polymeric amines of Examples 1 through 10 of U.S. Patent3,070,552 may be modified so as to contain tertiary amino end groups inaccordance with the present invention instead of secondary aminoterminal radicals as therein described.

EXAMPLE IV Thirty-one lbs. of polyethylene glycol 600 dichloride havingan average molecular weight of 628 was reacted with 1.64 lbs. of methylamine in ethylene glycol according to the method of Example 1, reactionbeing carried to 92.8% completion as measured by titration of ionicchloride in the reaction product. After reaction, cooling water wasapplied to the vessel and the pressure vented.

. The amount of unreacted covalently linked chlorine was calculated bysubtracting the ionic chloride from the total chlorine originallypresent in the polyethylene glycol 600 dichloride and three times thetheoretical amount (0.639 lb.) of dimethyl amine required to convert thecalculated amount of residual organically bound chlorine was added tothe autoclave. Heat was applied, the temperature being raised to -115 C.After 1 /2 hours at this temperature, the reaction mass was againsampled and titrated for ionic chloride, conversion being found to becomplete. Heating was continued for an hour longer at which timechloride titration showed no further change. After settling andsplitting of the aqueous bottom layer, fresh water was added to replacethat removed in the bottom layer, a homogeneous 20% active solution of apolymeric amine being thus obtained in which all of the chlorine endgroups were replaced by the dimethyl amino radical. The solution wasstable to storage over prolonged periods at 50 C.

Application of this material to Dacron taffeta fabric in the mannerdescribed in Example I by conjoint treatment of the fabric with Eponite100 and curing after drying, yielded a fabric possessing antistaticproperties comparable to those of the treated fabric of Example I.

The secondary amino end groups of the product of this example may beconverted to tertiary amine radicals by any of the methods of Examples Ito III. The products of Examples I to III derived from intermediatespecies (2) may also be reacted with excess dimethyl amine in a mannersimilar to that of Example IV, the residual terminal covalently linkedchlorine being thus replaced by tertiary amino groups. The final productof reaction in either case is the same, both end groups being tertiaryamino radicals as in the products of alkylation of intermediate species(1).

It will be understood from the foregoing description of this inventionthat the products thereof are applicable to hydrophobic textilematerials in any form, whether fiber, filament, yarn, knitted or wovenfabric, non-woven or felted fabric or the like.

Hydrophobic fibers are fibers which have a comparatively low capacity toretain moisture in comparison with such fibers as cotton and rayon. Suchfibers are, for instance, nylon fibers (e.g. those called Nylon 66 whichare prepared by condensation of 1,6-l1examethylene diamine and adipicacid; those called Nyon 6 which are prepared by polymerization of6-amino caproic acid); Orlon acrylic fibers (Orlon is a trademark of theE. I. du Pont de Nemours & Company) prepared by polymerization ofacrylonitrile; Dacron polyester fibers (Dacron is a trademark of the E.I. du Pont de Nemours & Company) prepared by condensation ofterephthalic acid and ethylene glycol; cellulose triacetate fibers(marketed under the trademark Arnel by the Celanese Corporation ofAmerica); Dynel fibers (Dynel is a trademark of the Carbide & CarbonChemical Company, a division of Union Carbide Corporation) which arecopolymers of acrylonitrile and vinyl chloride; Acrilan fibers (Acrilanis a trademark of the Chemstrand Corporation) and similar syntheticfibers.

It will be understood, of course, that the products of this inventionmay also be employed in the antistatic treatment of blends of any of theaforementioned or other bydrophobic fibers and of blends thereof withnatural fibers. The treatment of wool to impart antistatic propertiesthereto is also embraced within the scope of this invention.

The invention claimed is:

1. The process of treating hydrophobic textile materials whichcomprises: (a) impregnating a hydrophobic textile material with anaqueous solution of an antistatic agent comprising a water-solublepolytertiary amine while maintaining the pH of the antistatic agent onthe acid side, said antistatic agent having at least one terminaltertiary amino radical and having the structure:

wherein Y represents a tertiary amino radical NR R wherein R and R areeach selected from the group consisting of alkyl, hydroxyalkyl, aralkyland alkaralkyl radicals having 1 to 10 carbon atoms; Z is an organicdivalent radical derived from a polyglycol; R is a radical selected fromthe group consisting of alkyl, alkenyl and hydroxyalkyl radicals having1 to 22 carbon atoms; and Y is selected from the group consisting of (1)a tertiary amino group --NR R wherein R and R are each selected from thegroup consisting of alkyl, hydroxyalkyl, aralkyl and alkaralkyl radicalshaving 1 to 10 carbon atoms, (2) a secondary amino group HNR- wherein Ris the same as previously defined, and (3) a covalently linked radicalof the group consisting of a halogen, the ester forming residue of aninorganic acid, and organically substituted sulfuric, sulfonic andphosphoric acids; and p is an integer having a value of at least 1, andthen drying and curing the composition in situ.

2. The process of claim 1 wherein said antistatic agent is mixed with across-linkin g agent.

3. The process of claim 2 wherein the cross-linking agent is a member ofthe group consisting of polyepoxide, polyaziridinyl and polyethyleneglycol dihalide.

4. The process of claim 3 wherein the cross-linking agent is apolyepoxide and wherein an effective amount of zinc fluoborate ispresent as a catalyst.

References Cited UNITED STATES PATENTS 3,021,232 2/1962 Pretka ll7-l39.5X 3,070,552 12/1962 Tesoro et a]. 2602.1 3,258,358 6/1966 Cohen 1l7139.5

WILLIAM D. MARTIN, Primary Examiner THEODORE G. DAVIS, AssistantExaminer US. Cl. X.R.

ll7l38.8, 141,145

